It was composed by Mendler, Emanuel "Eman" Kiriakou, Jai Marlon, Laura Raia, David Ryan and Freddy Wexler.

The Maximum Pop Magazine said that "Top of the World" is lovely and catchy, the composition is solid and sweet and Mendler showed versatility.

[6] Kai of the magazine Embrace You commented that the intro of the song is attractive and sounds like "a dramatic melody straight out of a classic black and white film with captions instead of voices".

[9] Tim Sendra of AllMusic gave a positive review, praising Mendler's "fine singing voice" and her "songwriting chops".

[10] Xinhau of Spin or Bin Music was positive and commented that "Top of the World" sounds like "Ready or Not" and said "left me to question whether or not it was a conscious decision".